POST-CMOS COMPATIBLY MICROMACHINED HIGH-PERFORMANCE ON-CHIP AIR-CORE SOLENOIDAL INDUCTORS

摘要

This article reports on-chip micromachined solenoidal inductors with high radio-frequency (RF) performance. The RF components can be either used in multi-GHz telecommunication modules with a system in package scheme or monolithically integrated in RFICs with a post-CMOS integration method. A trench SiO{sub}2-refilling technique is used to shape the silicon cavity for accommodating the embedded inductor, and to mesh the substrate beneath the pads to suppress the substrate-loss at the pads. Without de-embedding needed, the tested inductors with 2.5-7 nH inductances achieve 33 to 13.5 peak-Q factors at 11-3 GHz and self-resonance frequencies of 18.0-7.5 GHz, respectively. Moreover, the inductors with the trench technique feature a high uniformity in RF-performances, thereby, showing a promise for practical product applications.